But the meandering script that they’re saddled with in the prison thriller Stone eventually frustrates us with its awkwardness and arbitrariness.

De Niro plays dependable, remote, churchgoing corrections officer Jack Mabry, handling a last case for his Michigan prison before he retires (as tired a movie cliché as there is).

He’s married to the quiet and deeply religious Madylyn, played by Frances Conroy, in a longtime hollow union tainted by a terrifying incident we see in an early flashback that reminds us that there are all kinds of prisons that folks spend their lives in: some have bars and some do not.

He tells her to look up Mabry on the outside and implies that she should see what she can do to tap into Mabry’s darkest impulses and perhaps help his case. Hmmm…

Mabry does indeed encounter Lucetta on the outside and his moral and ethical strength is surely tested, while Stone seems to be going through a religious conversion of sorts, embracing spirituality on the literal and figurative inside.

So while one man seeks retirement and the other parole, both sinners seek salvation.

Director John Curran (The Painted Veil, We Don’t Live Here Anymore) works from a script by Angus Maclachan that gets lost exploring the thin line between right and wrong. It never gets us to invest in its pivotal characters, who remain mouthpieces instead of eventuating into three-dimensional life in a misguided screenplay that assigns them narratively convenient behaviors that never come close to adding up.

Not that the film fails to hold us, but far too much of it rings false. And in the late going, continuity and transitions are so choppy and improbabilities so abundant that it feels as if there might be a reel missing.

It’s not so much that the story has nowhere to go in Act III, it’s just that it never goes anywhere illuminating.

Earlier in his career, De Niro would have played the convict, of course. Here he’s technically competent most of the time but not within shouting distance of inspired.

Norton is commanding and interesting, as usual, but his character disappears for long stretches. And Conroy is saddled with a thankless, underwritten role.

But Jovovich — not exactly sure what movie she’s in, in over her head (but, to be fair, not exactly helped by the clunky script) — finishes up just short of embarrassing.

What transpires between Lucetta and Mabry, absolutely critical for the story to be in any way plausible, never for a moment rings true. The blame for that is shared by De Niro, Jovovich, and the screenplay.

So we’ll grant parole to 2 stars out of 4 for an initially engrossing but ultimately unsatisfying prison drama, a four-hander that explores spiritual emptiness and awakening with distinctly uneven results.